Ms Bullock acknowledged that house prices are beginning to "pick up again" and the RBA (along with APRA, Treasury and ASIC) are "considering whether we might need to do more".

Advertisement

Advertisement

APRA began to put restrictions on residential mortgage lending in 2014, with a particular focus on investor loans. ASIC has also tightened its rules on responsible lending practices.

The macroprudential measures initially resulted in the proportion of investor loans falling below 10 per cent, but more recently that number has "started to spring up again", Ms Bullock said.

Nevertheless, the balance sheets of the four major banks (which APRA deems to be "systemically important") are now much more "resilient" to any potential housing downturn, she said.

"We're not not saying there won't be any losses, and it's not saying there will be no risks. But we are saying: if there is some sort of shake-out, these financial conditions won't dramatically affect the health of the economy," Ms Bullock said.

From a systemic standpoint, one of the big concerns for the RBA is that housing may be a 'procyclical' issue for the Australian economy.

"Is there evidence that people see prices rise and they think prices will always rise?" Ms Bullock asked.

If that is the case and speculators are "chasing prices", any housing slump would be "much bigger than it would otherwise be", she said.

Investors tend to be the first people to sell when house prices begin to dip, Ms Bullock said.

"We're focused on whether things might be procyclical and whether or not there are implications for the resilience of household balance sheets and banking balance sheets as well," she said.